The present invention relates to a drilling tool for working in metallic material, more precisely a tool of the type that comprises a tool body having at least one cutting insert exposed for working a workpiece. The tool may e.g. be formed as a drill having flutes extending in its longitudinal direction, which flutes join to the outer and inner inserts, respectively, in order to serve as grooves for chip release.
The present invention also relates to a damping device adapted to be arranged on a tool body.
At working of holes in metallic materials, problems arise with the high sound level caused by vibrations from the working and the machine sound. Hitherto known drills have not been provided with built-in/added damping devices formed in such a way that a suitable sound and vibration damping has been feasible. The essential thing is to be able to eliminate major parts of the vibration sound in the range that is uncomfortable to the ear. If possible, only the machine sound as well as the inevitable chip raffle which normally usually amounts to 74-76 dB should be left. However, without damping it is not uncommon that levels up to 130 dB have been measured. The proper machine sound feels more restful to the ear.
From SE-B-468 930 it is, for instance, previously known to form a drilling tool with a very stiff material, such as cemented carbide, disposed in the flutes which define the drill's chip channels, in order to stiffen the drill and thereby dampen vibration. However, the hard metal borders that result have not turned out to give any suitable silencing of noise.